Human right defenders shave sent a letter to Colombia President Juan Manuel Santos and the commander of the country’s second largest rebel group ELN urging them to sit down and begin peace talks, local media reported on Tuesday.

The letter signed by socialist House Representative Ivan Cepeda and human rights lawyer Alirio Uribe encouraged the two parties to start peace dialogues before the upcoming congressional election in March and the presidential election in May.

“Mr. President Santos, the country needs to walk in a definitive manner towards peace. You are conscious that this will not be possible without dialogue with the ELN, another actor [in Colombia’s armed conflict] that without a doubt has put its interest for negotiations on the table. This may not be denied by your government.”

The ELN has been seeking an official peace process with the administration in November 2012, shortly after the government initiated ongoing peace talks with the FARC, the country’s largest rebel group.

In the letter, the rights workers also hailed progress made during the ongoing peace talks with the FARC.

“It’s obvious that Colombia perceives the negotiations that are being carried out since 2012 with the FARC-EP with optimism, and that according to the negotiators’ statements have yielded concrete results,” the letter said.

However, the letter also called on the ELN to refrain from illegal activities and respect international humanitarian law.

“It is time that the ELN leadership sends a message to the Colombian people to reveal its interest in beginning the negotiation. Today, the abandoning of kidnapping, and respect for international humanitarian law, are signs of genuine political which will not go unnoticed by a people that thinks of renewed politics and the peaceful ways that enable its realization.”

“We place our experience as human rights defenders at the disposal of the parties . We believe in dialogue, the debate based on ideas, and of course, we hope that a Colombia in peace and respects human rights is possible,” the letter concluded.

The letter was read aloud Tuesday in the Bolivar Square in the country’s capital Bogota.